Flush valve



2 Shets-Sheet 2 R. H. z lNKlL l FLUSH VALVE Filed Nov. 27, 1929 Y May 31, 1932.

@aff/d# @gg/@a @him f )MM Y (Mm Patented May 31, les:

UNITED STATES PATENToI-Flca ROY E'. ZINKIL, 0F OAK PARK, ILLINOIS, .ASSIGNOB T CRANE CO., I' HICAGO, ILLHWOIS, A CORI'QRATIONOF ILLINOIS rLUsH vALvn Application led November 27, 1929. Serial No. 410.086.

This invention relates to water supply systems used in combination with drainage systems. 4Such a system, for example, is a water closet supplied with Water' through a flush 5 valve connected to one side thereof, the other side ofthe closet being connected to a drainage pipe. In flush valve installations lfor flushing water closets the fresh water inlet v is connected directly7 to the bowl and when 10 the valve is opened there is a direct passage from the water supply through the iush pipe to the bowl and thence to the waste or drainage pipe. It sometimes occurs that the drain from the closet becomes clogged causing the bowl to lill up to the level of the outlet therein from theflush valve. Under such conditions it is possible, and in actual4 use it frequently occurs, that a vacuum is created in the valve and piping adjacent thereto by reason of the fact that the valve has no vent into the air. As a consequence thereof, if

i there is a failure in the water supply, or the supplyis shut off, and a person attempts to draw water from the system from a` point below the clogged bowl, the water from the bowl may be siphoned back into the water supply line. If the water in the bowl happens to be soiled, this Water will be siphoned back into the fresh water of the supply line and contaminate the supply line. Such an action'is liable to occur' in single closet installations and is even more likely to occur y where a series of fixtures are being fed from a single riser or supply line. In such an instance, if one xture became clogged as heretofore mentioned and the supply was cut off for some reason, leaving a head of Water in the riser, any attempt to obtain water from the riser would-probably result in a siphon- .40 ing action causing the water from the clogged bowl to be drawn into thesupply line.

It is the purpose of this invention to provide means to prevent this back siphoning of the water from the bowl into the supply line.

Accordingly, means are provided for venting the system at' some point` such as, for example, in the outlet side or low pressure side' of Ithe Hush -valve to the air, thereby breaking or preventing therformation 4of a vacuum in 3 .the valve as described. The vent may be inserted at any suitable place along the system, such as, for example, in the iushpipe between the valve and the outlet into the bowl or in the valve chamber.

In one form of this invention the vent may comprise a check valve inserted in the bonnet of the flush valve over the low pressure or outlet side thereof. This arrangement is particularly suitable for iiush valves having the auxiliary-valve in the bonnet and has 6o many advantages, one of which is accessibility and another is that the vent is then made at the highest point in the system, thus positively insuring a vent to the atmosphere.

One particular illustration of this invention will be given in connection with the drawings, in which:

Fig. 1 is a plan of a valve embodying a vacuum breaking vent in accordance with this invention,

Fig. 2 is a vertical section through the center of the valve,

' Fig. 3 is a vertical section through the center of the valve along a plane perpendicular .to that of Fig. 2, Fig. 4 's an enlarged sectional detail of the vacuum break check valve, n

Fig. 5 is a perspective sectional view of the body of the check'valve,

Fig. 6 is a perspective of the valve ele- 30 ment, and

Fig. 7 is a diagrammatic sketch illustrating a typical plumbing system in which a back siphoning is likely to occur.

In the illustrated form of this invention there is shown a' portion of a supply and drainage system employing a flush valve and including a flush pipe l, such as is ordinarily connected to a water closet bowl (not shown) The upper end of the iiush pipe is connected to the body portion 2 of a flush valve 3 by means of the usual coupling 4. The valve mechanism of the flush valve forms no part of this invention and may be of any suitable automatic type, generally employed in ush valves. In the illustrated form one standard type of flush valve is shown comprising a body portion 2 and a bonnet portion 6 secured thereto by a threaded collar 7. Within the body portion there is mounted trols communication between inlet duct 14 and discharge or outlet chamber 17 leading to adischarge passage 18 formed in the side of the body portion and leading to the discharge end 19 of the flush valve. The bonnet 6 also carries the usual oscillating handle 21 which actuates the plunger 22 for tipping valve 16 oft' its seat. The above described valve is merely shown and described for purposes of illustration, and as heretofore stated, forms no part of this invention.

The system is vented to the atmosphere to prevent the formation of any vacuum there- .pressure or discharge chamber 17.

by causing a back siphonage, by means of a check valve threadedly secured in an internally threaded boss 23 formed integrally with the bonnet portion 6 and having a passage 24 therethrough leading into the low The check valve comprises a body portion 26 threaded to engage boss 23 and a cap portion 27, the latter threadedly engaging the body portion and having a plurality of apertures 28 through the outer wall thereof and communicating with a central bore 28al in the cap. The latter bore is in communication with a central bore 29 in the body portion which is reduced in diameter at the upper end of the body to produce a seat 30. A valve element havmg a square shank portion 31 of proper dimensions to fit freely Within bore 29 and a rounded seat 32 is slidingly mounted within the body portion 26. The end of the shank portion of the valve element may be slotted as at 33 topermit the insertion of a screw driver to enable the seating portion 32 to be ground in against the seating portion 30. The shank portion of the valve element is of greater diameter than the passage 24 which prevents the valve element from falling into chamber 17.

The construction and assembly of the check valve is shown particularly in Fig. 4, from which it can be seen that air may enter aper tures 28, pass between the flat sides of the shank portion 31 of the valve and the bore 29, and thus enter chamber 17 through duct 24. If any back pressure occurs in chamber 17, it will close the check valve and thus prevent any leakage of water through the .check valve. From the above description it 1s also apparent that the system is vented to the atmosphere by means of the opening through passage 18, chamber 17 and valve 26. In view of the fact that the check valve The bonnet@ portion carries the tip valve 1G which conis inserted at the highest point in the flush valve, the possibilities of the check valve becoming inoperative by reason of being filled with water are reduced to a minimum.

It is believed that the operation of this system and particularly the function of the check valve is clear from the above description and that the action may briefly be summarized as follows:

Assinning a condition in which the outlet of closetitnot shown) is stopped up and the bowl is lleidwith water to overflow or to a level which wouldyseal the flush pipe 1 and. the supply to 'thelluslr valve has been shut off at one of the lowerfloors, or at the inlet to the building, an operator opening any fixture on this line on any ofthe floors below the flush valve wouldallow the\\w\ater to flow out of this fixture which is beinguoperated which would create a vacuum 1n the piping )and flush valve and would Siphon the water from the'flooded bowl into the supply line contaminating the fresh water supply. This contaminated water might then be drawn out at any fixture in the system unless some method is employed to prevent this back siphonage. This vacuum is created in inlet l2 and chambers 13 and 14. However, the formation of such a vacuum will be prevented by reason of air entering through the ports 28 of check valve 2G. The preventing or breaking of this vacuum by the admission of air will prevent any back siphonage of the soiled Iwater'in the bowl into the fresh water supply. It is obvious that in other types of flush valves the vacuum may tend to take place in other portions than chambers 13 and 14 or inlet 'l2 of the valve and that the particular structure of the automatic valve mechanism and associated chambers illustrated in the foregoing flush valve is merely given for purposes of illustration, the essential feature being to prevent the formation of any vacuum which may be created in the system and thus prevent any back siphonage action through the valve.

Figure 7 shows a typical layout of part of an installation to demonstrate how the vacuum is caused in the supply pipe line 34. Assume that the closet bowl 35 at one of the upper floors is stopped-up so that the water has flooded the bowl to overflowing thereby submerging the end of the flush pipe in the closet, and that supply valve 36 at one of the lower floors has been closed; anyone opening faucet 37 to draw 4water will draw the water that is in the supply line above the faucet. Siphonic action is created in the fixtures connected to the supply pipe line above the faucet, due to the displacement of the water. Consequently, the water in the closet bowl will be drawn into the supply line throuo'h Athe flush valve and contaminate the supply line. This formation of the vacuum in the Hush valve can be prevented by a suitable means of admitting air from the atmosphere to the inner parts of the valve, thus preventing the siphonic action.

It is obvious that many changes ma?)r be' made in the details of construction wit out departing from the spiritv and scope of the invention as defined in the appended claims.

I claim: l. A flush valve comprising an inlet, an

outlet, automatic valve'mechanism including a v alve seat disposed therebetween, and means for venting said valve comprising a normally open check valve located above said valve seat and connecting the interior of said valve to the atmosphere to prevent back l siphonage therethrough.

2. A flush valve comprising'an inlet, an outlet, automatic piston type valve mechanism including a valve seat disposed therebetween, and means in said valve located above'the valve seat for venting said valve comprising a. check valve connecting the low pressure chamber of said valve to the atmosphere to prevent back siphonage therethrough, said check valve comprising a valve body having a cylindrical bore therein and a valve element seated in said bore, said element having a polygonal shank terminating in a round seating head.

so 3. A flush valve comprising a body portionand a bonnet portion, means for securing Y said portions together, automatic valve mechanism mounted within said portions, said l bonnet portion having ducts therein communicating with the inlet and outlet sides of said valve, and a normally open check valve connected to said bonnet and arranged to admit air into said bonnet to prevent backv siphonage therethrough.

4. In a water supply system the combination of a source of water, a flush valve having a main valve and seat therefor and a flush I pipe connected thereto with a normally open check valve in Said valve located above the main valve seat of said iush valve in said system arranged to permit entry of air into said system to prevent back siphonage from said pipe to said source of water.

In witness of the f regoing I affix my signature.

v ROY H. ZINKIL. 

